The forked bone in the chest of a bird shaped like the letter V; two people traditionally pull it apart and make wishes.
From 'wish' (hope or desire) and 'bone' (skeletal structure). The word combines English elements, though the tradition of pulling the bone likely has medieval European roots.
The wishbone tradition might come from Roman augury where priests read omens in birds' bones—so Thanksgiving's silly wish-making is actually a 2,000-year-old religious practice disguised as a game.
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